[seqfan] more strangeness (A000079 "Powers of 2" and many others)

Joerg Arndt arndt at jjj.de
Thu Mar 4 12:11:26 CET 2010

Dear Vincenzo,
in seq A000079 you give:

  Except for the first term, number n such that if A=(7/8)*n^4;
  B=(7/16)*n^4; C=(17/16)*n^4; D=(5/4)*n^4; then A^3+B^3+C^3=D^3 [From
  Vincenzo Librandi (vincenzo.librandi(AT)tin.it), Sep 08 2009]

This is just an obfuscated way of saying that
  (7/8)^3 + (7/16)^3+ (17/16)^3 == (5/4)^3

Further, the statement has nothing whatsover to do with the sequence
at hand (plus the initial qualification is plain wrong).

Kindly remove the comment including the corresponding example which

  For n=2, A=14, B=7, C=17, D=20, and 14^3+7^3+17^3=20^3 [From
  Vincenzo Librandi (vincenzo.librandi(AT)tin.it), Jun 25 2009]

In addition, please do the following search in the database:
  librandi -author:librandi

There seem to be more examples of relations that need
to be removed, a quick glance suggests to firstly check:
A005408 (see my last mail)
A000668 (!)
A004526 (!  a(n)=floor(n*[sqrt(5)-sqrt(3)]) wrong!)
A002145 (!)
(and apparently many more, I just checked 2 of 255 pages)

best regards,  jj

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